The present invention relates to a device for stacking sheets sequentially coming out of an image forming apparatus on a tray.
A copier, printer or similar image forming apparatus has a tray for accommodating sheets each carrying an image thereon. For example, Japanese Patent Laid-Open Publication No. 233458/1990 proposes an image forming apparatus having a tray capable of stacking both of stapled sheets and non-stapled sheets, as needed. In this construction, non-stapled sheets are driven out one after another by a discharge roller and let fall onto the tray simply by gravity. This brings about a problem that the sheets cannot be neatly stacked on the tray, preventing, for example, different jobs from being clearly distinguished when a shifting operation is effected.
Although some implementations have been proposed to eliminate the above problem, none of them is fully satisfactory.